Process of forging gear blanks



June 1927' c. A. BRAUCHLER PROCESS OF FORGING GEAR BLANKS Filed ot. 4, 1922 3 .S heets-Sheet l gwugnfoz June 14 1927.

c. A. BRAUCHLER PROCESS bF FORGING GEAR BLANKS 4, 1922 5 Sheets-Sheet 2 Filed Oct.

grvuanto'o cAfimuC/Z r 'qw aw June 14, 1927.

C. A. BRAUCHLER V PROCESS OF FORGING GEAR BLANKS Filed Oct. 4, 1922 s She ets- Sheet Patented June 14, 1927.

UNITED STATES CHARLES A. BRAUCHLER, OF CANTON, OHIO.

success orroneme GEAR .BLANKS.

Application and October 4, 19a! Serial No. 592,276.

This invention relates to forged ,metal gear'blanks and a processo'f forging the same and has for its objects to produce agear blank from a blank cut from a metal bar, in which the teeth of the finished gear willbe made from metal originally at the surface of the bar, the grain of the metal flowing from the centerto the periphery of the wheel and back towardthe center.

' It is well known that the center of any bar of steel is the least refined portion of the same, due to the fact that being the most remote from the-surface,- itreceives the least working during the working of,

the bar. For this reason, the ,greatest amount of defects and impurities are always I Located through the axial center of a steel ar. It is also well known that all bar steel has a grain running parallel to the direction of rolling or axis of the bar, this grain being closer and more refined around the periphery of the bar, while in the central portion of the bar, the grain is" comparatively coarse.

The invention may be attained by cutting or cracking a blank from a steel .bar, the blank. being of a length greater than itsdiameter, heating the blank, and upsetting. the same endwise to produce a barrel shaped or double truncated cone and then placing the partly completed product in a forging die. and forging the gear blank therein, the outside grain of the metal-thus being caused to flow outward around the periphery of the gear blank, placing the most refined portion of thegrain in the portion of the gear blank from whichfthe .teeth are out, this, of

course, being the portion of the gear which stands the greatest wear, while the center of the gear which requires the least strength and is oftenremoved altogether, is formed from the central portion of the bar which has the least refinement and which contains the greatest amount of defects and impuri-- .ties. I

A preferred embodiment of the invention is illustrated in the accompanying drawings, in which I Figure 1" is a perspective View of the blank from which the gear blank is formed;

Fig. 2, a sectional view through the upsetting and forging dies by means-of which the gear blank is formed;

Fig. 3, a detail sectional view ofthe upsetrtllffg die, Showing the-same in the o ien position, a blank being located therein;

Fig. 4, a similar view showing the u setting die in the closed position, the part y completed product-being shown in section;

Fig. 5, a detail sectional View of the forging die showing the same in the open position, the upset blankbeing shown in posi tion therein;

. Fig. 6, a View of the forging die in the closed position, the finished gear blank being shown in section therein; Fig. 7; an enlarged, transverse, sectional view of the finished gear blank; and

Fig. 8,11 similar view of the finished gear formed therefrom.

Similar numerals indicate corresponding parts throughout the drawings.

In Fig, 1a blank is illustrated .at 1 which is cut, cracked. or otherwise severed from a rolled bar in a'manner to produce square or flat endsupon the blank as at 2. It will be noted that the'blank is of a length considerably greater than its diameter, this being preferable in order that the grain of the metal may flow properly when the blank is forged in the .dies, as hereinafter described. I

The dies in which the gear blank is formed are preferably of the form shown in Fig. 2, and comprise the u per and lower die blocks .3' and 4; respectively, the lower block being fixed and the upper block arranged to reciprocate by means of a hammeror the like. These blocks are provided with the upsettingdie 5 and the forging die 6 located adjacent to each other to facilitate the forming of the gear blank, the uncompleted product being removed from the upsetting die and placed-in7the forging die while still hot for the finishing operation.

The upsetting die comprises the lower inverted frusto-conical portion 7 and the up-' per frusto-conica-l portion 8 registering therewith and provided at its top with a tentering point 9. As'shown in Fig. 3, the

grainof the blank lis refined around the periphery as indicated. atflO, while the grain through the central portion of the blank as shown at 11 is less refined-and contains impurities andimperfections. v

It is the intention of the resent invention-to cause the more .refine grain at the periphery of the blank to flow outward from the center, placing the same in the portion of the gear blank from which the teeth are cut, while theless refined grain remains at the axial center of the gear blank, at thepoint where the least strain and wear is placed upon the gear. I

As shown in Fig. 3, the reduced bottom of the lower upsetting die 7 is of the same diameter as the blank 1. permitting the blank to be placed therein and properly con tered as shown in Fig. The blank 1 is heated to a red heat and placed in the lower upsetting die as shown in Fig. 3."

\Vhen the upper die descends upon the blank shown in Fig. 3. the blank. will be upset, assuming the barrel shape or double truncated conical shape asshown at 12 in Figs. 4 and 5, the point. 9 in the upper upsetting die forming a centeringsocket 13 in the upper end of the blank.

As shown in l igs. 4 and 5, the outer re fined grain 10 will be caused to flow outward toward the peripheral center of the uncompleted product. the axial. less refined grain reniaining'through the axial center thereof. as shown at 11.

The product 12. while still hot, is then in-" verted and placed i n the lower forging die which is shaped as shown at 14. and pro- .vided in its bottom with a centering point die is of a size to fit the adjacent end -.of.

the blank 12. as shown in Fig. 5.

The upper forging die 17 'is' provided in its top with a centering point 18. As the upper forging die descends, the blank will be forged into'the completed gear blank shown at 19, the refined grain .10 of the met 1 flowing outward from the hub portion 20 to the teeth portion 21. while the less refined grain 11 remains through the axial center of the gear blank.

The centering point 18 will form a socket 22 in the axial center of the gear blank upon the side opposite to the socket 13 providing means for easily centering the blank for machining the same.

As best shown in Fig. 7, all of the refined portion of the grain of themetal flows outward from the hub portions into the teeth portion of the gearblank. the axialcenter of the same containing all of the coarser grain and the imperfections and defects.

This central portion of the gear blank may be cutout as shown at 23 in the finished gear 24 illustrated in Fig. 8, the teeth 25 than the diameter thereof. upsetting the blank endwise producing' a barrel shaped product and placing the barrel shaped product ina forging die and forging the same endwise, causing the outer grain of the blank to flow outward from the hub portions into the teeth portion of the gear 2. The method of forming gear blanks consisting in cutting a flat ended blank from a bar ..said blank having a length gieater than the diameter thereof. upsetting the blank endwis. producing a barrel shaped product, inverting said product in a forging die and forging the same endwise, causing the outer grain of the blank to flow out-ward from the hub portions into the teeth portion of the gear blank.

3. The method of forming gear blanks I consisting in cutting a flat ended blank from a 'bar, said blank having a length greater than the-diameter thereof. heating the blank, upsetting the blank endwise producing a barrel shaped product. placing the product in a forging die while still hot and forging the same endwise, causing the outer grain.

of the blank to flow outward from the hub portions into the teeth portion of the gear blank.

4. The method of forming gear blanks consisting in cutting a flat "ended blank from a bar, said blank having a length greater than the diameter thereof, heating the blank, upsetting the blank endwise. produeing a barrel shaped product. placing said product in a forging die while still hot and forging the same endwise. causing the i outer grain of the blank to flow from the hub portions into the teeth portion of the gear blank.

CHARLES A. BRAUCHLER. 

